The diagnostic trials, conducted in Kenya (Sidindi and Kandara), Malawi (Thuchila, Nkhata bay, Kasungu), Mali (Koloko, Finkolo and Kontela), Nigeria (Ibi, Pampaida), and Tanzania (Kiberashi, Mbinga), constitute the major part of AfSIS agronomic activities. These are designed as nutrient omission trials to identify which of the macro-nutrients N, P and K are limiting crop growth. Further, there are treatments where lime, manure and multi-nutrients were added to diagnose other possible constraints related to soil chemical characteristics (e.g. acidity), availability of secondary and micro-nutrients or soil organic matter content.
Details on treatments description, site selection and characteristics, experimental design and layout, trial establishment and management, field measurements for plant growth, phenology and harvest and, handling of soil and plant samples can be found in the “Diagnostic Trials: A field Guide” booklet available as PDF here.
Table 1: Treatments implemented in the diagnostic trials within AfSIS
|T.8||NPK +lime (optional)|
Treatments implemented in the diagnostic trials within AfSISTreatments implemented in the diagnostic trials within AfSISSince diagnostic trials could not determine optimal rates for nutrient application, nutrient response trials were conducted to determine appropriate rates of N and P through response curves for N (0, 45, 90, 120, 150 kg N ha-1) and P (0, 15, 30, 40 kg P ha-1). Except for nutrient applications rates, all other agronomic practices in the nutrient response trials followed the same guidelines as the diagnostic trials. Prior to the AfSIS midterm review in early 2011, ISFM trials had been initiated in selected sentinel sites (i.e., Kiberashi, Nkhata Bay, Thuchila, Koloko, Kontela and Sidindi) and their design and objectives varied by sentinel site. The protocols for the ISFM trials are available at the CIAT-AfSIS portal through the links below. Since these ISFM trials do not offer insights beyond the specific sites of implementation, no further information is provided here for these.
The sites where agronomic trials were conducted in AfSIS Phase I are shown (in yellow dots) below:
Figure 1. Sites where diagnostic trials are conducted in AfSIS Phase 1